Cinder client does not honor disable_ssl_certificate_validation

The Client() class should pass in insecure as the value of
CONF.identity.disable_ssl_certificate_validation, otherwise many
tests will fail if the cinder server is secured with SSL.

Change-Id: I9bb6ff48a0d53b5b124e58c9959c9a43da8c7e5c
Closes-Bug: 1298019
diff --git a/tempest/clients.py b/tempest/clients.py
index 7ebd983..7552f76 100644
--- a/tempest/clients.py
+++ b/tempest/clients.py
@@ -524,6 +524,7 @@
         auth_url = CONF.identity.uri
         region = CONF.identity.region
         endpoint_type = CONF.volume.endpoint_type
+        dscv = CONF.identity.disable_ssl_certificate_validation
         return cinderclient.client.Client(self.CINDERCLIENT_VERSION,
                                           username,
                                           password,
@@ -531,6 +532,7 @@
                                           auth_url,
                                           region_name=region,
                                           endpoint_type=endpoint_type,
+                                          insecure=dscv,
                                           http_log_debug=True)
 
     def _get_object_storage_client(self, username, password, tenant_name):